Biomedical ultrasound has been shown to induce various biological perturbations including reduction in growth rates and mitotic indices, chromosomal anomalies, decreases in macromolecular syntheses, and induction of cell lysis. The proposed research includes an analysis of whether or not ultrasound induces indirect effects on organized cell systems, on whether or not chromosomal anomalies, of a type known to be induced in a plant system, are induced in mammalian cells, and whether cell cycle kinetics of proliferating cell systems are perturbed (and to what extent) by ultrasound. The overall objective of the proposed research is to obtain information on the sensitivity of cells to diagnostic-therapeutic levels of ultrasound.